L9396

Product Overview

The STMicroelectronics L9396 is a fully integrated high-voltage smart power device designed primarily for driving inductive loads such as DC motors, solenoids, and relays in automotive and industrial applications. It is a dual H-Bridge driver featuring built-in diagnostics, overcurrent protection, thermal shutdown, and other advanced features, which simplify system design and improve reliability. The device operates from a wide supply voltage range and provides robust current capability suitable for controlling two independent DC motors or one bipolar stepper motor.

The L9396 integrates power MOSFETs and control logic in a compact SO-20 package, offering a solution optimized for harsh environments with strong immunity to automotive transients and noise.

Key Features

* Dual full-bridge driver suitable for driving two DC motors or one bipolar stepper motor
* Wide supply voltage range: 8 V to 45 V
* Peak current capability up to 2.5 A per bridge
* Built-in overcurrent detection with open-drain status output
* Thermal shutdown with automatic recovery
* Under-voltage lockout (UVLO) to ensure safe operation
* Cross-conduction prevention logic (dead-time insertion)
* Diagnostic feedback signals for motor status and fault reporting
* High noise immunity and automotive-grade robustness
* Integrated bootstrap diodes for high-side MOSFET drive
* CMOS-compatible logic inputs
* Reverse battery protection and load dump robustness

Applications

* Automotive seat adjustment motors
* Power window and sunroof drivers
* Mirror and antenna motors
* Industrial actuators and robotic drives
* Bipolar stepper motor control
* HVAC systems in vehicles
* General purpose inductive load driving

Electrical Characteristics

| Parameter | Typical Value / Range |
| ---------------------------------------------- | ----------------------------------------------- |
| Supply Voltage (V_CC) | 8 V to 45 V |
| Output Peak Current per Bridge | 2.5 A peak |
| Continuous Output Current | Up to 1.6 A (per channel, depending on cooling) |
| Logic Supply Voltage (V_DD) | 4.5 V to 5.5 V |
| Input Logic Voltage Level | CMOS compatible (0 to 5 V) |
| Standby Current | < 1 mA |
| Overcurrent Detection Threshold | Typically 3.5 A (latched) |
| Thermal Shutdown Threshold | ~150°C (typical) |
| Output Saturation Voltage (V_DS(on)) | ~1.4 V at 1 A |
| Switching Frequency | Up to 20 kHz (PWM controlled) |
| Operating Temperature Range | –40°C to +150°C |

Functional Description

The L9396 integrates two full H-bridge drivers, each consisting of four MOSFETs arranged to drive one inductive load bidirectionally. The device supports PWM modulation for speed control and direction control via dedicated input pins. It features internally generated dead-time to avoid shoot-through, ensuring safe operation of power MOSFETs.

The internal diagnostic circuit continuously monitors current levels and temperature. In the event of an overcurrent condition, the device latches the outputs off and signals a fault condition through an open-drain fault output pin, allowing external microcontrollers to detect and respond accordingly. Thermal shutdown protects the device from damage during excessive temperature conditions by disabling the outputs until safe temperatures are reached.

The L9396 supports brake function by enabling shorting of motor terminals to quickly stop motor rotation, which is useful in precision motion control.

Pin Configuration and Interfaces

* Input Pins: Six logic inputs (IN1A, IN1B, IN2A, IN2B, EN1, EN2) for controlling direction, speed, and enable signals for the two bridges.
* Diagnostic Outputs: Fault (FLT) open-drain pin indicating overcurrent or thermal fault conditions.
* Power Pins: Supply voltage (VCC), ground (GND), logic supply (VDD).
* Motor Outputs: Four output pins (OUT1A, OUT1B, OUT2A, OUT2B) connecting to the motor windings.
* Bootstrap Capacitor Pins: Internal charge pump for driving high-side MOSFETs without external gate drivers.

Protection Features

* Overcurrent Protection: Detects short circuits or stall conditions by sensing load current, latches outputs off to protect the device and load.
* Thermal Shutdown: Prevents damage by disabling outputs when junction temperature exceeds preset threshold.
* Undervoltage Lockout: Ensures the device only operates when supply voltage is within safe limits.
* Reverse Battery and Load Dump Protection: Enables robust operation in automotive environments subject to supply voltage transients.
* Cross-Conduction Prevention: Internal logic ensures that high- and low-side MOSFETs in the same half-bridge never conduct simultaneously.

Thermal and Mechanical Details

The L9396 comes in a SO-20 plastic package with an exposed pad for improved thermal dissipation. Proper PCB layout with adequate copper area is recommended to maintain device temperature within specifications under high current load conditions. The package size and pin configuration allow easy integration into standard automotive and industrial motor driver boards.

Typical Application Circuit

The device is commonly used with minimal external components:

* Decoupling capacitors on supply pins to stabilize voltage rails.
* Bootstrap capacitors for high-side driver operation.
* External microcontroller or logic device to provide input control signals.
* Motors connected directly to output pins.
* Optional pull-up resistors on fault output for open-drain signaling.

Summary

The STMicroelectronics L9396 is a robust, feature-rich dual H-bridge motor driver module tailored for demanding automotive and industrial inductive load applications. With integrated high-voltage MOSFETs, comprehensive protection mechanisms, diagnostic feedback, and simplified interface logic, it reduces system complexity while enhancing reliability and safety. Its wide supply voltage range and high peak current capability make it a versatile solution for driving DC and stepper motors in harsh environments requiring precise and dependable control.